Bone Breaker (5e Feat)
From D&D Wiki
You have trained hard to master unarmed combat.
- Increase your Strength or Dexterity score by a +1 to a maximum of 20.
- Your unarmed strikes score a critical hit on a 19-20.
- When you score a critical hit with an unarmed strike, the target must make a Constitution saving throw (DC = 8 + your Strength or Dexterity modifier + your proficiency bonus). If they fail, choose one of the following effects:
- The target has disadvantage on attack rolls until the end of their next turn.
- The target is knocked prone.